Setup.exe

Search *.msi from setup.ini and call it.

[Product0]
MsiPath1=Installer64\hogehoge.msi

When the previous version of *.msi is installed,

msiexec /i Installer64\hogehoge.msi REINSTALL=ALL REINSTALLMODE=vomus

else

msiexec /i Installer64\hogehoge.msi